CT of mediastinal lymph nodes in patients with non-small cell lung carcinoma.

What is the "bottom line" for the role of CT in staging mediastinal involvement in patients with non-small cell bronchogenic carcinoma? On the basis of their studies, Libshitz and McKenna question whether CT has any utility in evaluating mediastinal lymph nodes. Staples et al believe that CT and mediastinoscopy are complementary, and that many patients who are considered candidates for surgical resection should have both. It is clear that the overall sensitivity and specificity of CT are variable from study to study. In recent studies that have subjected patients to exhaustive lymph node dissection, and in which there has been meticulous correlation between the lymph nodes identified on CT and those removed at surgery, it seems clear that the sensitivity of CT in predicting the absence of metastatic disease is unacceptably low. However, there is another way to approach these statistics. Recent studies have shown that patients with mediastinal microscopic metastasis discovered at the time of thoracotomy have improved survival rates if the primary tumor and mediastinal metastases are all resected. Patients with macroscopic metastases in mediastinal nodes have a worse prognosis. Therefore, CT may be useful for screening patients to rule out the presence of macroscopic metastatic disease. If the mediastinal CT scan shows no enlarged lymph nodes, it seems reasonable to bypass the surgical staging procedure and proceed directly to thoracotomy. However, in order to determine the true pathologic stage of disease in the patient, a thorough mediastinal dissection must be carried out in these patients at the time of thoracotomy.(ABSTRACT TRUNCATED AT 250 WORDS)